A resin composition based on a polymer and such an ester is known from U.S. Pat. No. 4,311,624. This publication describes a resin composition, which contains film-forming components such as drying oils, alkyd resins and vinyl addition polymers, and a mixture of (a) a dicyclopenenytloxyalkyl ester of an ethylenically unsaturated mono- or dicarboxylic acid and (b) a (meth)acryloxyalkyl ester of an unsaturated fatty acid. The compounds mentioned as (a) and (b) are also known as reactive diluents.
Such resin compositions are particularly used as binding agents in coating compositions. Nowadays, efforts are made to use coating compositions with a lower percentage of, or even without (the so-called `100%-solids system`), volatile solvents on account of the environmental problems connected with the use of these organic solvents and the associated environmental laws. One of the possibilities of solving these problems is to use reactive diluents in the resin compositions for coating compositions. These diluents are usually compounds with a low viscosity and a high boiling point, or low saturated vapour pressure, which act as solvent during the process but can subsequently also ba polymerized along with the rest of the compound. In this manner the environmental pollution caused by the conventional solvents can be reduced. The requirements to be met by these compounds are such that on the one hand they can be used as cross-linking agents and that, on the other, they contribute towards the good properties that a coating composition is required to have.
A disadvantage of the resin compositions based on a polymer and the known reactive diluents and the resulting coating compositions is that the monomers used as reactive diluents are too volatile and/or the properties of the resulting coating compositions, such as the drying properties, do not meet the requirements and/or the monomers to be used as reactive diluents are difficult to prepare and very expensive and/or the monomers are insufficiently soluble and do not mix sufficiently with the polymers and/or the reactive diluents do not have an optimum diluting effect.